Refrigeration



Nov. 17, 1942.

P. P. ANDERSON, JR

REFRIGERATION Filed Jan. 23, 1940 BY M22" 2 Sheets-Sheet l W W MAW.

" MATTORNEY.

Nov. 17, 1942. P. P. ANDERSON, JR

REFRIGERATION Filed Jan. 25, 1940 2 Shets-Sheet 2 0/ 7 m 1 \V v o 4 3 I R 2 4 3 /v WW I MIIV A a a R 3 3 m a a 4 y\ r n/ 4 4 INVENTOR. W n fl/M mmm.

Patented Nov. 17, 1942 ,UNITED STATES PATENT OFFICE REFRIGERATION PhilipP. Anderson. In, Evansville, Ind., assignor to Servel, Inc., New York, N. Y., a co po ltion v of Delaware ZClaims.

This invention relates to refrigeration, and is particularly concerned with the splitting or dividing of liquid in refrigeration systems into a plurality of paths of fiow. 1

In refrigeration systems it is often desirable to split liquid from a single body into a plurality of quantities or to divide a stream of liquid into a plurality of paths of fiow. This is particularly true in absorption refrigeration systems of large size in which consideration must be given to several factors among which may be mentioned the height, capacity and efficiency of the system.

, By splitting a stream of liquid into several paths of flow, as at an evaporator or absorber or at both of'these places, for example, the circulation of liquid in the refrigeration system is such that the capacity and efficiency of the system are improved and advantages may also result in effecting a reduction in the height of the system.

In accordance with the invention, liquid circulating in a refrigeration system is divided into a plurality of paths of fiow by producing a body of liquid in a pocket or chamber into which liquid is introduced, and flowing liquid from such body through orifices or restrictions which are below the liquid surface level of the body and at substantially the same height. The orifices or restrictions are of such size that the liquid surface level will stand some distance above the level of the orifices. By making theorifices or restrictions substantially the same in size, equal division or splitting of liquid into a plurality of paths of flow is obtained. By making the orifices of different size, the liquid may be divided togive any definite unequal splitting into several paths of flow. Further, a vent is provided for the several paths of liquid flow and also for the pocket or chamber whereby pressure equalization of these parts is effected and trapping'of gas in the pocket is prevented to insure that the liquid divider will function properly.

It is an object of the invention, therefore, to provide an improved liquid divider for refrigeration systems and of the character described above.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the claims. The invention, both as to organization and method, together with the above and other objects and advantages thereof will be better understood as I next describe-my improved liquid divider embodied in an absorption refrigeration system like that described in panying drawings, which form a which is embodied a liquid divider embodying my.

invention;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1 to illustrate more clearly the manner in which the liquid divider is embodied in the refrigeratlon system;

Fig. 3 is a horizontal sectional view, taken on line 3-3 of Fig. 4, of the liquid divider shown in Figs. 1 and 2;

Fig. 4 is a vertical sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a horizontal sectional view similar to Fig. 3, taken on line 5-5 of Fig. 6, illustrating another embodiment of the invention; and

Fig. 6 is a vertical sectional view similar to Fig; 4 and taken on line 6-6 of Fig. 5.

In Figs. 1 and 2 I have shown the present improvement embodied in an absorption refrigeration system of a type containing a pressure equalizing agent and like that described in the aforesaid application of Albert R. Thomas. Such a system includes a generator ill, a condenser l l an evaporator l2, and a plurality of absorbers l4. The system contains a solution of refrigerant in absorption liquid, such as ammonia in water, for example, and also an auxiliary agent or inert gas, such as hydrogen.

The generator III is heated in any suitable manner, as by a gas burner ii, for example, whereby refrigerant vapor is expelled from solution in generator ill. The refrigerant vapor fiows through a conduit l6 into a vessel l! which together constitute a liquid analyzer. From vessel l1 refrigerant vapor fiows upward through a conduit l8 and an air-cooled rectifier l9 into a first section Ila of condenser II in which vapor is liquefied. Refrigerant vapor not liquefied in condenser section I la fiows into a second condenser section llb. Refrigerant vapor liquefied in condenser section ll b flows through a conduit 20 into chamber 2i into which liquid also flows tor l2 flows from the lower part thereof through a conduit 25, an outer passage 21 of a gas heat exchanger 25, a conduit 29 and branch conduits 30 into the lower parts of absorbers l4, as shown most clearly in Fig. 2.

In absorbers M the rich gas mixture flows countercurrent to downwardly flowing weak absorption liquid which enters through conduits 3| I divider 45, as will be de- The absorption liquid aband 32 from a liquid scribed hereinafter.

, sorbs refrigerant vapor from the inert gas, and

inert gas weak in refrigerant flows from the absorbers |4 through conduits 33, a plurality of 4 tubes 34 forming an inner passage of the gas heat exchanger 25, and conduit 25 into the upper part of evaporator l2.

The circulation of gas in the gas circuit just described is due to the diil'erence in specific weight of the columns of gas rich and weak, respectively, in refrigerant vapor. Since the column of gas rich in refrigerant vapor and flowing from evaporator |2 to absorbers I4 is heavier than the gas weak in refrigerant vapor and flowing from the absorbers l4 to evaporator l2, a force is produced or developed within the system for causing circulation of inert gas in the manner described.

Absorption liquid enriched in refrigerant flows from the lower parts of absorbers l4 through conduits 35, and 31, an outer passage of liquid heatexchanger 35, conduit 39, vessel I1 and conduit i5 into generator l0. Absorption liquid from which refrigerant vapor has been expelled flows from generator l5 through a conduit Hi into a coil 45 which is also heated by the gas burner l5. Absorption liquid is raised in the system by vapor-liquid lift action from coil 40 through a tube 4| into a separating chamber 42. The lifting vapor is separated from the raised liquid and flows from chamber 42 through a conduit 43 into generator I; and this "vapor, together with refrigerant vapor expelled'from solution in the generator, flows upwardly into the condenser II, as explained above.

The raised absorption liquid flows from separating vessel 42 through a conduit 44, an inner passage of liquid heat exchanger 38, and. conduit 45 into the liquid divider 45 which will be described presently. This circulation of absorption liquid results from the raising of liquid through tube 4|.

Heat liberated with absorption of refrigerant vapor in the absorbers i4 is transferred to a suitable cooling medium which circulates through coils 41 arranged in thermal exchange relation with the absorbers. As shown, the coils 41 are connected by conduits 45 and 49 to air-cooled condensers 55. Each coil 41 and condenser 55 and interconnecting conduits forms a closed circuit which is partly filled with a volatile liquid that vaporizes in the coils 41 and liquefles in the condensers 50. The liquid evaporating in the coils 41 takes up heat from the absorbers l4, and the vapor liquefying in condensers 55 gives up heat to surrounding air.

In coil 23 liquid refrigerant flowing from condenser to evaporator I2 is precooled by evaporation of refrigerant into rich gas which flows from and to the gas heat, exchanger 28 through conduits 5| and. 52.

The outlet end of second condenser section ||b is connected by conduits 25 and 53, vessel 54, and conduit 55 to the gas circuit, as to one of the conduits 33, for example, so that any inert gas which may pass through the condenser can flow .divider 4,5, as explained into the gas circuit. Refrigerant vapor not liquefied in condenser ii flows through conduits 25 and 53 to displace inert gas in vessel 54 and force such gas through conduit 55 into the gas circuit. The effect of forcing gas into the gas circuit in this manner is to increase the total pressure in the system to insure condensation of refrigerant vapor in condenser As shown most clearly in Figs. 2 to 4 inclusive, the liquid divider 45 includes a vessel 55 forming a chamber 51 into the lower part of which extend the conduits 3| and 32. The upper ends of conduits 5| and 22 are provided with caps 55 and 59 having orifices or flow restricting openings 55 and 5|, respectively. The upper ends of conduits 3| and 32 are connected by conduits 52 and 52 to a conduit 54 which is connected at its lower end to the upper part of vessel 55 and at its upper end to the outlet end of condenser II, as shown in Fig. 1. The conduits 52, 53 and 54 serve as vent conduits for the liquid divider 45 whereby pressure equalization is effected between the upper ends of conduits 3| and 32 and the vapor space of chamber 51 and also to prevent trapping of gas in the latter.

During operation of the refrigeration system, absorption liquid weak in refrigerant flows from generator I5 through conduit 45 into liquidabove. The force to cause this circulation of absorption liquid is relatively small because the flow of absorption liquid from vessel '42 to liquid divider 45 and thence through the absorbers l4 back to generator l5 takes place by force of gravity. The surface level of the body of liquid formed in chamher or pocket- 51 is maintained some distance above the upper ends of conduits 3i and 32, as at the level A in Fig. 4, for example, due to the restriction to flow of liquid through the orifices 55 and 5|. The caps 55 and 55 are at exactly the same level, and, when the liquid level in chamber 51 is above the caps, liquid will trickle through the orifices 55 and 5|. with this arrangement liquid is effectively split or divided into two paths of flow even though circulation of absorption liquid is effected in the system by the force of gravity. The liquid divided into two paths of flow is conducted by force of gravity through conduits 3| and 32 to the absorbers i4 whereby refrigerant vapor is absorbed out ofthe inert gas, as explained above.

With the absorbers |4 being the same size, as shown in Fig. 2, it is preferable that the orifices 55 and 5| are the same size so that equal division of liquid into the conduits 3| and 32 is effected. It may be desirable in some instances,

as when the absorbers are not the same size, for

example, tn effect an. unequal distribution of liquid. In such case the orifices 55 and 5| are of different size so that the desired unequal splittin 'g or division of liquid is effected.

In Figs. 5 and 6 is illustrated another embed ig ment of the invention in which the vent con:

dults 52 and 53 in the embodiment described above are dispensed with and instead venttubes 55 and 55 arev connected to the caps 55 and 55. The vent tubes 55 and 55 establish communication between the upper ends of conduits 3| and 32 and the vapor space in chamber 51. The chamber 51 is connected by the vent conduit 54 to the outlet end of the condenser, as in the embodiment in Figs. 2 to 4 inclusive and shown in Fig. 1, whereby objectionable trapping of gases in the vapor space of chamber 51 is avoided The upper ends of vent tubes 55 and 55 are near cient in dividing liquid into a plurality of paths of fiow even when the force effecting circulation of liquid is relatively small, as in the refrigeration system described above in which force of gravity is utilized to cause circulation of the absorption liquid.

' l'he caps 58 and 59 preferably are formed of relatively thin metal so that no capillary forces are involved in the flow of liquid through the orifices 60 and BI. Consequently, the liquid should flow through the orifices 80 and 6| as soon as the orifices are covered with liquid; and, as the liquid levelf-rises in chamber 51, the

, rate of flow of liquid increases, the rate of flow being proportional to the square root of the liquid head on the orfices. In refrigeration systems of the type described above and in which the present improvement is embodied, the importance of having the orifices at the same level is due to the low liquid head contemplated above the orifices. same level, a variation in liquid head above the orifices results in considerable change in the rates of flow of liquid through the orifices.

While I have shown and described several embodiments of my invention, it will beapparent to those skilled in the art that modifications and changes may be made without departing from the spirit and scope of the invention. Thus, the liquid divider may be incorporated in other parts of the refrigeration system to divide liquid, such as, for example, to divide liquid refrigerant flowing to a plurality of evaporators. I therefore do If the orifices are not at the i rator to said places of fices at a plurality not wish to be limited to the embodiments shown in the drawings and described in the specification, and I intend in the following claims to cover all modifications and changes which fall within the true spirit and scope of the invention.

, What is claimed is:

1. In an absorption refrigeration system having a generator in which refrigerant vapor is expelled from absorption liquid, a condenser for liquefying the expelled vapor, an evaporator in which the liquid refrigerant is evaporated, means forming a plurality of places of absorption, and members for conducting'vapor from said evaporator to said places of absorption, means forming a pocket for liquid, means for conducting weakened absorption liquid to said pocket, means for restricting flow of liquid downward from said pocket forming means at a plurality of places below the liquid surface level therein, and means for conducting liquid entirely below said surface level from each of said last-mentioned places to said places of absorption.

2. In an absorption refrigeration system having a generator in which refrigerant vapor is expelled from absorption liquid, a condenser for liquefying the expelled vapor, an evaporator in which the liquid refrigerant is evaporated, means forming a plurality of places of absorption, and members for conducting vapor from said evapoabsorption, means forming a pocket for liquid, means for conducting weakened absorption liquid to said pocket, oriof places below the liquid surface level in said pocket for permitting restricted flow of liquid therefrom, conduits for conducting liquid from each of said last-mentioned places to said places of absorption, and means to vent the upper ends of said conduits and the vapor 40 space of said pocket forming means. I

PHILIP P. ANDERSON, a. 

